Trace halogen salt



Patented Nov. 29, 19 49 II-ACE HALOGEN SALT Joseph A. Dunn, SLOlalr. Mich" and Frank G.

Miller, Denville. N. J

Foods Corporation. New

tion of Delaware aeaignoretoGenes-al York, N. Y., a eel-peca- No Drawing. Application June 15. ms. Serial No. ram

Claims. (01. "-2) This invention relates to the addition of trace mineral supplements to the normal animal diet (including humans as well as domestic animals and fowls) and more particularly to the incorporation of such supplements in salt and the prevention of loss thereof from the salt before consumption. This application is a continuationin-part of our prior applications Serial Nos. 704,285 and 704,286, flied October 18, 1940, both now abandoned.

A few principal mineral elements make up the continues to be lost in spite of the most effective greater part of the mineral content of the animal body, including calcium, magnesium, sodium, potassium, phosphorous, sulphur and chlorine. The average animal diet is fairly well supplied with these principal mineral elements. However, other dietary minerals are utilized in very small amounts as compared with the principal mineral elements so that they are commonly referred to as trace elements," and it is well known that the normal animal diet often fails to supply even the very small daily requirements of certain of these trace elements. The dietary supplements required to meet such deficiencies may vary from time to time and from place to place as the constitution of the normal diet varies.-

Accordingly the addition of trace element eupplements to the diet is frequently necessary or desirable. These supplements must of course be edible in the sense that the small amounts actually ingested do not cause objectionable toxic effects, and also such that the trace elements per se become available to the animal during digestion. when such very small amounts of trace element supplements are simply mixed with the far larger volumes of food normally consumed,

it is diillcult to obtain uniform administration to individuals. However, salt is a universal constituent of the animal diet which is consumed in small but fairly constant daily rations, and for these reasons salt is an excellent medium for incorporating trace element supplements in the diet. The desired supplements are simply mixed with the salt in proportions that will furnish appropriate amounts of minerals, taking into account the requirements of the animal and the daily ration of salt consumed. Because the daily consumption of salt is small, the much smaller ration of trace element supplement may amount to as much as 24% by weight of the salt in some cases, although usually it will be less than 1%.

Thus it has been proposed to add trace element supplements to salt for use on the table or in the kitchen or for feeding animals, especially iodine in the form of potassium iodide.

In many instances, however, salt to which such trace element supplements have been added is found to be substantially or completely devoid of trace elements when consumed after a relatively measures that can be devised to prevent oxidation (see for example Hart Patent No. 2,144,160. Bhumaker et al PatentNo. 2,164,089, see Patent No. 2,170,611, Russell Patent N0. 2.331.424, and

Whitmoyer Patent No. 2,882,193) Furthermore, the same loss has been observed in the case of non-volatile and non-oxidizable .trace elements such as trace metals.

We have discovered that the above mention losses are due in large part, if not entirely, to solution of the trace element compounds used in water -or salt brine and actual leaching out of the compounds from the salt mass. Although salt is a very advantageous medium from the above standpoints for incorporating trace element supplements in the diet, it is also very hygroscopic and absorbs large amounts of moisture from the atmosphere. As moisture continues to be absorbed by the salt, water or salt brine gradually percolates through the salt mass and collects at or drips from the bottom of the mass. The trace element compounds are present only in very small amounts and moreover are admixed in ilnely divided form with th salt so that they are distributed as small particles on the surfaces of the salt crystals and constitute a sort of external phase which tends to be preferentially dissolved. Under these conditions, the small amounts of trace element compounds are rapidly dissolved, even though they may be only very sparingly soluble in water or salt brine.

Such percolation of moisture with the eflects described above takes place not only in loose salt but even in the salt blocks which are placed at suitable points as salt licks for cattle and other animals, as for example in feeding sheds, in the open near; feeding or watering places, or often on stakes in the open field. These blocks, usually in 50 lb. sizes, are conventionally made by compressing ordinary salt under pressure of the order of ten tons per square inch, resulting in dense solid masses that are practically vitreous in character and apparently are substantially impervious. However, their density is not equal tothe density of solid crystalline salt, the specific gravity of which is 2.16 whereas the specific gravity of salt blocks is 2.02 plus or minus depending on thepressure used and the crystalline character of the salt. Thus the blocks contain about 7%. of void spaces and to this extent are porous or capillary in nature. We have found that moisture deposited and/or absorbed at the surface of such a block gradually diffuses or percolates throughout th block underthe influence of capillary action and gravitation.

The percolating moisture first dissolves both short period of time. In the case of iodine, this 5. salt and trace element compounds from the surface layer of the mass of salt and, as the solution percolatcs inwardly and downwardly through the mass, its concentration of both trace element compound and salt progressively increases until it passes out of the bottom. Percolation takes place under humid conditions regardless of whether the salt is exposed to light and/r raln or not; in other words, the same loss of trace elements occurs during storage of the salt in the dark in a humid warehouse or .the like, particularly if the relative humidity of the surrounding atmosphere is above the critical range for salt of 70-75%. The surface layer oi the salt is first very rapidly depleted of trace elements which migrate both toward the center of the salt mass and toward its bottom. The zone of surface depletion steadily increases in depth and the concentration of trace elements in the interior first rises and then rapidly falls as the trace element compounds are lost by escape of the percolating solution from the bottom of the mass.

Thus complete depletion of a 50 lb. salt block may occur within to 60 days simply by exposing it to a humid atmosphere, and this depletion is quite independent of illumination or exposure to sunlight. More important, however, is the fact that practically complete depletion of the surface layer may take place within a very few days, after which animals licking the bloc:

get nothing but salt because the rate of consumption of the block is seldom if ever as great as the rate of increase in depth 02 the depleted surface It makes no difference how much trace element is retained in the center of the block if there is none in the surface layer licked by the animal. The same loss of trace elements occurs even more rapidly in the case of masses of loose salt because of the greater porosity of the mass and the relative ease with which moisture may enter and percolate through the mass. In this case the efiect of surface depletion can be reduced by stirring or agitating the mass, but this is not feasible during storage and is seldom practiced once the salt is placed in the feed trough for the animals. Even in the ordinary salt shaker or open salt cellar used in the kitchen or on the table, it is a common experience in damp, humid weather to find drops or water or brine orcrusted salt adhering to the shaker or cellar, usually at the bottom of the salt mass. Trace element compounds originally distributed throughout the salt become concentrated in such liquid phases and to a. large extent remam in the shaker or cellar when salt is removed therefrom.

The chief object of the present invention is to prevent such losses of trace element suppie= ments and to maintain the compounds in uniform admixture with the salt regardless of the conditions to which it may be exposed so that the intended supplementation of the diet is secured as the salt is gradually consumed.

The present application is directed particularly to the three trace halogens iodine, fluorine and bromine which are frequently desirable as dietary supplements. Reference is made to our copending applications Serial Nos. 33,223, 33,225, and 33,226 filed concurrently herewith and directed to supplementation of the diet with other supplemental minerals.

We avoid depletion of trace halogens due to percolating moisture by the use of trace halogen compounds that are substantially insoluble in the moisture taken up by the salt and in the brine solution resulting from percolation of this moisture through the salt. Complete insolubility is not necessary, the limiting condition being that the ratio of solubility of the compound in water containing 042.6% NaCl to the solubility of salt in water should not be substantially greater than the original ratio of said compound to the salt. As previously indicated, the amount of each trace of halogen compound will usually be less than 1%, although in special cases 2-3% may be used. The ratio of solubllitics must be limited accordingly. If this limiting value is exceeded, the trace of halogen compound will be dissolvedand lost at greater rate than the salt and depletion will take place, beginning in the surface layer of the salt as stated above. If the limitlng value is maintained. however, the proportion of compound to salt, particularly in the surface layer of the salt, will remain unchanged although of course there will be a gradual loss in total weight of the salt mass. At less than the limiting value of the solubility ratio, on the other hand, th proportion of trace halogen compound to salt will increase somewhat not only in the mass as a whole but also at its surface.

It will be understood that such insolubility in water containing G-26% NaCl must be coupled with a substantial degree of solubility in the digestive fluids found in the gasLro-intestinal tract of the animal, in order that the trace of halogen itself may become available to the anirnal during digestion.

The relative solubilities of a particular trace halogen compound in brine and of salt in water may be ascertained from known data or determined by experiment if such data are not available. In this connection, it is known that the solubility of a substance in a solution is a function of the concentration of other substances in the solution. It is also known that the dispersibility of colloidal material in a solution is a function of the amount of electrolyte present in the solution. These two phenomena are highly important factors in the present invention because the moisture taken up by the salt and percolating through it may vary in salt concentration from zero to saturation (i. e., 0-26%) Some compounds increase in solubility in salt brine as the salt content increases while others decrease in solubility, being more soluble in pure water. Still others exhibit their maximum solubility or dispersibility at intermediate salt concentrations. For the purposes of the present invention, the compounds used should be substantially insolubig and non-dispersible (i. e., non-peptizable in the true colloidal sense) in water containing ll26% salt.

Instead of ascertaining relative solubilities, a simple method of determining whether the dosired conditions will be obtained with any given compound is to analyze the drip from a test sample held in an atmosphere of high humidity. As long as the proportion of trace halogen, compound to salt in the drip does not exceed substantially the original proportion of said compound to salt in the test sample, the retention of the trace halogen in the salt is satisfactory.

In using this testing method, we have found it satisfactory to employ the following procedure. Small test blocks (approximately 5 gm. in weight) were formed with a laboratory hydraulic press applying pressures equivalent to those used in the commercial production of salt blocks. A series of these small blocks were suspended over suitable test tubes and exposed to a relative humidity of or higher for 43 hours after which the blocks and the respective samples of drip collected in the test tubes were analyzed for their salt and trace halogen content. For convenience the results of these analyses were expressed in terms of the percentage of the original content of trace halogen compound remaining in the test block, 100% retention meaning that none of the trace halogen was lost in the drip.

Under the above test conditions, the salt loss from a test block will vary from 5% to Hence retention figures in the range 90-95% refiect equal rates of loss of trace halogen and salt. In other words, the proportion of trace halogen to salt in the block after the test and also in the drip is the same as in the original block. Retention values above 90-95% indicate loss oi salt at a faster rate than trace halogen and a consequent increase in concentration of the halogen in the block. On the other hand, retention values of less than 90-95%, particularly those less than 85%, indicate that the trace halogen is being lost at a sufficiently faster rate than the salt to result in undesirable depletion of the halogen from the salt. A striking example of trace halogen loss was found in the case of a test block containing stabilized potassium iodide of the type commonly used in commercial blocks heretofore. Under the conditions of the above test, such blocks were found to have retention values of only 5-35%, meaning that 65-95% of the original iodide content had been lost in drip from the block.

We have correlated results obtained in such rapid retention tests with practical experience when 50 lb. cattle blocks are held in damp warehouses or exposed in the field, and have determined that when retention values of about 85% and higher are obtained with the rapid retention test, the corresponding commercial blocks are effectively stabilized against loss of trace halogen compounds. We have ,also demonstrated that when retention values of 95-100% are obtained with the rapid retention test, the corresponding commercial blocks when stored in damp warehouses or exposed in the field will actually increase in their proportion of the trace halogen compound because the salt is preferentially dissolved. This increase is particularly evident at the surface of the block where the trace halogen is immediately available to the animal at all times.

In case the trace halogen supplement is to be incorporated in loose salt, the foregoing test procedure can be simplified and at the same time brought into closer conformity with practical conditions by suspending a small mass of the loose salt in a bag or on a screen which allows passage of the drip. Preferably the bag or screen should be of materi .1 that does not absorb appreciable amounts of the percolating solution, as otherwise retention of salt and/or trace halogen compound in the material may complicate the analysis.

The useful compounds of the trace halogens are subject to the three basic requirements men tioned above, namely, that they are edible (l. 9.; non-toxic), that they are soluble in the digestive tract, and that they are substantially insoluble in water containing 0-26% salt. Within these limitations, however, many difierent types of compounds of the above trace halogens will be found suitable. For example, suitable types of trace halogen compounds are the halogenated in-, soluble alkaline earth soaps of higher fatty acids such as stearic, behenic, brassidic, palmitic, etc.; halogenated fats of high molecular weight, and halogenated insoluble proteins. The insoluble halogenated heavy metal soaps of higher fatty acidsmayalsobeusedasasourceoi'thetraee halogen as well as of heavy metal trace elements such as iron and copper. In addition there are a number of miscellaneous types of stable and insoluble iodinated organic compounds of high molecular weight that give excellent retention and are physiologically acceptable. Inorganic halogen compounds may also be used. It will be evident that the compound may include more than one trace element, as for example the combination of a trace halogen and a trace metal.

The following compounds are listed as exampiesz Fluorinated casein Calcium fiuorostearate Calcium fiuorobehenate Magnesium fluorostearate Magnesium fluorobehenate Calcium bromostearate Calcium bromobehenate Magnesium bromostearate Tetra-iodo phthalic anhydride 3,5 diiodo 4 hydroxy benzaldehyde Dithymol diiodide Fluorite (CaFz) Sellaite (MgFzl Apatite (CaF2.3Cas.P:O:)

In case an otherwise suitable com ound is found subject to .decomposition by light or oxidation, it may be stabilized against such deterioration by any suitable method such as those disclosed in the patents mentioned above.

Assuming that all three of these trace halogens are to be incorporated in the block, the following formula may be used:

Per cent Dithymol diiodide 0.0175 Calcium fluoride 0.005 Calcium bromobehenate 0.01 Salt (NaCl) Suil'.lcient to make It will be understood that the particular trace halogen compounds that are listed in the above formula are only by way of example and that any other suitable compounds can be substituted therefor. Also the amounts of the trace halogen compounds given in the formula are based on the amounts of the trace halogens per se that are desired in the animal diet, and where other compounds are substituted they should be used in amounts determined on the same basis. On the other hand, the amount of any particular trace halogen that is needed will depend upon the nor.

some mal constitution of the animal diet in the region where the salt is to be used. Hence the proportions or trace halogen compounds given above are sub ect to considerable variation, but will usually be less than 1%. In special circumstances where abnormally large supplies or a particular trace halogen are desired, larger amounts up to about 3% may be used. It may also be desirable to vary the constitution of the salt mass by omitting ute quantities of iron, copper, manganese, etc.,

may be present as impurities and exert a marked catalytic enect tending to cause oxidation and decomposition with liberation of free iodine. A great deal of efi'ort has been expended in devising ways of stabilizing such iodine compounds against these catalytic eiiects, as shown by the patents mentioned above.

Insoluble halogen compounds such as those mentioned above are much less afiected by metallic impurities so that the stabilization measarcs of the prior art are not needed as a rule, although they may be used if desired. When, however, the salt is further supplemented by the deliberate addition of appreciable amounts of trace metals, and when the trace metal compounds used are soluble, then even the insoluble halogen compounds of the present application may be destabilized. In this case undue loss of halogen may occur in spite of the use of the various prior stabilization measures mentioned above. We have found that this undesirable effect of trace'metal supplements is avoided by the use-of insoluble trace metal compounds such as those disclosed in our copending applications mentioned above. In other words, when salt is to be supplemented by the addition of both trace halogens and trace metals, both should be added in the form of compounds that are substantially insoluble in Water containing -26% salt, not only to prevent loss by solution in percolating moisture but also to prevent interaction that would result in decomposition of the trace halogen compound and loss of free halogen.

In the case of salt blocks, it isoften desirable to color the supplemented blocks to distinguish them from ordinary blocks. The trace halogen compounds and/or other trace mineral supplements may provide sufficient coloring for this purpose. Thus lazurite, which is a source of nutritional sulphur, produces a blue color. Pigments may be added if desired, and diiIerent colors may be used to differentiate blocks of varying composition.

In controlling deficiency diseases by dietary supplements, one of the major problems is to secure approximately uniform administration of such supplements to individual animals because of the very small amounts needed, the practical difiiculty of distributing such small amounts uniformly throughout feed mixtures, etc. It will be seen that salt embodying the present invention eliminates such difliculties and provides a very convenient and practical means of administering trace elements to animals in uniform controlled amounts. The consumption of salt by an animal difierent regions.

such as a cow, for example, will be reasonably uniform in amount depending on the daily requirement of we animal and is not materially anected by the presence of a small proportion of supplementary materials. 'The present invention makes it possible to disperse such materials throughout a mass of salt in definite uniform concentration, although they are present in amounts as small as a, traction of a per cent in proportion to the salt, and also to maintain such concentration substantially unchanged as the salt is consumed. Hence each daily, approximately constant ratio of salt consumed by the animal contains a definite, predetermined amount of the desired supplementary materials.

In the same way, the invention may be utilized advantageously to administer trace elements and biologicals to animals for the stimulation of the animal metabolism in various respects. Such administration may be desirable even though there is no deficiency in the normal animal diet. For example, it has been found that production of milk and butter fat can be increased by the temporary administration of thyroprotein (e. g., iodinated casein) in amounts substantially above the normal requirements of the animal. This administration can be effected simply and controlled accurately by the use of salt containing appropriate amounts of thyroprotein either alone or in combination with other trace mineral supplements that may be desired. Excessive amounts of other dietary supplements may be administered in the same manner whenever desired.

It will be understood from what has been said above that the invention in its broad aspect is not restricted to any particular trace halogen or to any particular combination thereof, since the choice of those to be used will depend on the constitution of the normal diet and will vary in In the case of any particular trace halogen, moreover, suitable compounds of wide variety are available and selection may be made largely on the basis of availability and cost. The amounts of such compounds to be used can be determined from the normal daily requirement of the animal for trace halogen in proportion to its daily consumption of salt, which may vary with difierent animals, and from the degree of deficiency of the normal diet of the animal.

Hence reference should be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. Salt containing a trace halogen supplement to the animal diet and of the type having dispersed therethrough an edible compound of a trace halogen of the group consisting of iodine, fluorine and bromine, said compound being sub- I stantially soluble in digestive fluids whereby said trace halogen is made available to the animal during digestion but substantially insoluble in water containing 026% salt so that it is not dissolved by moisture absorbed by and percolating through the'salt.

2. Salt containing a trace halogen supplement to the animal diet and of the type having dispersed therethrough not more than 3% of an edible compound of a trace halogen of the group consisting of iodine; fluorine and bromine, said compound being substantially soluble in digestive fluids whereby said trace halogen is made available to the animal during digestion but the ratio of the solubility of said compound in water containing 0-26% salt to the solubility of salt in water being maximally substantially equal to the ammo compound to the prising a dense solid mass of compressed salt having dispersed therethrough an edible compound of a trace halogen of the group consisting of iodine, fluorine and bromine, said compound being substantially soluble in digestive fluids whereby said trace halogen is made available to the animal during digestion but substantially insoluble in water containing -26% salt so that it is not dissolved by moisture absorbed by and percolating through the block.

4. A salt block containing a trace halogen supplement to the animal diet and of the type comprising a dense solid mass of compressed salt having dispersed therethrough not more than 3% of an edible compound of a trace halogen of the group consisting of iodine, fluorine and bromine, said compound being substantially soluble in digestive fluids whereby said trace halogen is made available to the animal during digestion but the ratio of the solubility of said compound in water containing 0-26% salt to the solubility of salt in water being maximally substantially equal to the ratio of the proportion 01 said compound to the proportion of salt in the block.

5. Salt containing trace mineral supplements to the animal diet and of the type having dispersed therethrough an edible compound of a trace halogen of the group consisting of iodine, fluorine, and bromine and an edible compound of a trace metal, said compounds being substantially soluble in digestive fluids whereby said trace halogen and trace metal are made available to the animal during digestion but substantially insoluble in water containing 026% salt so that they are not dissolved by moisture absorbed by and percolating through the salt and said halogen compound is stable in the presence of said trace metal.

6. A salt block containing trace mineral supplements to the animal diet and of the type comprising a dense solid mass of compressed salt having dispersed therethrough an edible comanimal during digestion, the ratio of the solubility of said compound in water containing 0-26% salt to the solubility of salt in water being maximally substantially equal to the ratio of the proportion of said compound to the proportion of salt.

9. Salt having dispersed therethrough not more than 3% of a bromine supplement to the animal diet in the form of an edible bromine pound of a trace halogen of the group consisting of iodine, fluorine, and bromine and an edible compound of a trace metal, said compounds being substantially soluble in digestive fluids whereby said trace halogen and trace metal are made available to the animal during digestion but substantially insoluble in water containing 0-26% salt so that they are not dissolved by moisture absorbed by and percolating through the salt and said halogen compound is stable in the presence of said trace metal.

7. Salt having dispersed therethrough not more than 3% of an iodine supplement to the animal diet in the form of an edible iodine compound that is substantially soluble in digestive fluids whereby iodine is made available to the animal during digestion, the ratio of the solubility of said compound in water containing 0-26% salt to the solubility of salt in the water being maximally substantially equal to the ratio of the proportion of said compound to the proportion of salt. I

8. Salt having dispersed therethrough not more than 3% of a fluorine supplement to the animal diet in the form of an edible fluorine compound that is substantially soluble in digestive fluids whereby fluorine is made available to the compound that is substantially soluble in digestive fluids whereby bromine is made available to the animal during digestion, the ratio of the solubility of said compound in water containing 0-26% salt to the solubility of salt in water being maximally substantially equal to the ratio of the proporton of said compound to the proportion of salt.

10. A salt block containing an iodine supplement to the animal diet and of the type comprising a dense solid mass of compressed salt having dispersed therethrough an edible iodine compound that is substantially soluble in digestive fluids whereby iodine is made available to the animal during digestion but is substantially insoluble in water containing 0-26% salt so that it is not dissolved by moisture absorbed by and percolating through the block.

11. A salt block containing a fluorine supplement to the animal diet and of the type comprising a dense solid mass of compressed salt having dispersed therethrough an edible fluorine compound that is substantially soluble in digestive fluids whereby fluorine is made available to the animal during digestion but is substantially insoluble in water containing 0-26% salt so that it is not dissolved b moisture absorbed by and percolating through the block.

12. A salt block containing a bromine supplement to the animal diet and of the type comprising a dense solid mass of compressed salt having dispersed therethrough an edible bromine compound that is substantially soluble in digestive fluids whereby bromine is made available to the animal during digestion but is substantially insoluble in water containing 0-26% salt so that it is not dissolved by moisture absorbed by and percolating through the block.

13. A salt block for feeding animals having not more than 3% dithymol diiodide dispersed therethrough.

14. A salt block for feeding animals having not more than 3% of an alkaline earth fluoride dispersed therethrough.

15. A salt block for feeding animals having not more than 3% calcium bromobehenate dispersed therethrough.

JOSEPH A. DUNN. FRANK G. MILLER.

anrmtiiucns ormn The following references are of record in the file of this patent:

UNFE'I'ED STATES PATENTS 

